Tools electronic gauges diminishing returns?

First, I like many of you love tools; mine are the best without being gold plated. So, electronic gauges.

What is the difference between a paper slide rule for sup/super heat and an a three hose setup? Assume a Appion vacuum line, etc with core removal, etc. if so inclined.

With hoses the units are north of $400 and seem subject to the same issues as the new phones. Blue tooth does not go around corners and appears limited to line of sight.

The Sporlan unit requires an I Pad. So if electronics are necessary and you are going to tote your I phone isn’t there an app that lets you enter the numbers and come up with the answer skipping the electronic stuff? Is toting the fancy box around easier than a manifold with 2 gauges – think 32 foot ladder.

Second point. Evacuation to 20 microns or so. One poster commented he didn’t remove the schrader valves, sucked and ran. If there is a filter dryer, does it really make any difference? If the moisture goes into the dryer, and if there are no leaks, isn’t it job done?

This is not an invitation for poor workmanship, just a question regarding diminishing returns. I hate call backs, I hate remakes, I hate not feeling like I have done my job.

But back to the beginning, a brass manifold, three hoses and two gauges, and a paper slide rule seems like a hard combination to beat. If you drop the manifold, replace a gauge, drop the electronic, and well, what happens when you drop your fancy phone? The computer between your ears goes up and down a ladder very easily with the rest of you, delicate gauges and a tool kit not so much so. Likewise, lose the slide rule, second one in truck, drip the I pad, second one in the truck?